This invention relates to a dry cell powered lighting device of the type which can be used in different modes, one mode being a flashlight mode to provide a directed beam, and another being a lantern mode being to provide an area light or lantern to provide a multi directional spread of light.
Lighting devices of the aforementioned type have been developed relatively recently and have proved to be commercially successful due to the wide range of applications for which such a light is suitable. One prior art light of this type is described in PCT Patent application No. PCT/AU94/00271 which application has proceeded to grant in Australia and other countries.
The lighting device has a tubular body in which slides a tubular area lens. At the end of the tubular area lens is a portable flashlight lens. The dry cell or cells are in their own cartridge carrier, and once assembled the tubular area lens slides in an annular space between the cartridge and the body. When the lighting device is in its flashlight mode the cylindrical lens is retracted into the body of the device thereby positioning the lamp at the focal point of a reflector which is mounted to the cylindrical lens. When the device is in lantern mode the cylindrical lens is slid forward, out of the body of the device so that the lamp is positioned rearward of the reflector and at the approximate centre of the cylindrical lens.
The arrangement consists of three sub-assemblies namely the lens sub-assembly, the battery cartridge sub-assembly and the body sub-assembly.
The numbers of sub-assemblies and moving parts renders the lighting devices expensive to make, and complex to assemble.
Further, complex moulds are required so as to provide rib structures and grooves to ensure that parts will be correctly assembled and will slide smoothly. This adds to the cost of production. One of the difficulties of the prior out lights is the need to increase the function of the area lens portion and its movement relative to the body and the cartridge. A complex system was devised to hold an O-ring on the area lens which engages a groove in the battery cartridge or the body, and the groove is of a complex shape to provide detents or stops at several locations.
This adds more parts as two O-rings are required which need to be hand assembled to the area lens. The complexity of the structure necessitates assembly of the body, cartridge and area lens in a specific sequence.
The body of the lighting device has, as mentioned above, an annular recess into which the cylindrical lens is receivable and the requirement to provide this recess complicates both the structure of the device and the manufacturing process. The device, for these reasons, is reasonably costly to produce and also the device produced in this manner is not particularly robust, and is fairly bulky. Also, the form of the body is dictated by the configuration of the cylindrical lens which accordingly restricts the range of designs which can be produced using this sliding lens arrangement.
According to a first aspect of the invention there is provided a lighting device comprising:
a generally tubular body having a dry cell cavity adapted to contain one or more dry cells for powering the lighting device, the body having a rearward end and a forward end,
a cylindrical translucent lens fixedly mounted to the forward end of the body,
a lamp mounted to the body at or adjacent to the forward end thereof, said lamp adapted to be electrically connected to dry cells contained within the body,
a generally parabolic or cone shaped reflector slidably mounted relative to the cylindrical lens and located within the interior of the cylindrical lens, the reflector having an opening in the centre thereof shaped to receive at least part of the lamp therethrough, and
the reflector being slideable in an axial direction between an extended position in which the reflector is spaced away from the lamp and light emitting from the lamp in use shines through the cylindrical lens, and a retracted position in which the lamp extends at least part way through the opening in the reflector, and light emitting from the lamp in use is reflected in a forward direction by the reflector.
Preferably the reflector is mounted to a sleeve which is slidably mounted to the cylindrical lens.
The body may be of lesser diameter then the cylindrical lens and a tapered transition section may join the body with the cylindrical lens. The tapered transition section may be translucent and it is preferably formed integrally with the cylindrical lens.
The cylindrical sleeve is preferably of larger diameter than the cylindrical lens, the sleeve having an inner surface which is slideable relative to the outer surface of the cylindrical lens. There may be sealing ring located between the lens and the sleeve. The scaling ring may comprise a ring seal mounted on the inner surface of the sleeve and slideable on the outer surface of the lens. The sleeve preferably has a transparent disc or cover sheet on the forward end thereof adapted to protect the reflector and the lamp.
Preferably the lamp is mounted on a removable mounting plate or hub which, when removed, exposes the dry cell cavity to allow for dry cell replacement. The lamp is preferably mounted so as to be positioned approximately adjacent the rearward end of the cylindrical lens. Where the lamp is mounted on a removable plate or hub, this plate or hub preferably has peripheral formations thereon adapted to engage with co-operant formations on the body to keep the lamp positioned and centralised.
Preferably the lighting device also includes a strap having a first end pivotally connected to the body and a second the other end having a quick release or bayonet fitting thereon, the body including a first receiving socket therein adapted to receive said second end therein, and the cylindrical sleeve including a second receiving socket for receiving the second end therein, the cylindrical sleeve being locked in position relative to the cylindrical lens when the second end is operatively located in said second socket
According to another aspect of the invention there is provided a lighting device comprising:
a generally tubular body having a dry cell cavity adapted to contain one or more dry cells for powering the lighting device, the body having a rearward end and a forward end;
a generally cylindrical translucent lens slideably mounted to the outside of the body and extending forwardly of the forward end of the body;
a lamp mounted to the body at or adjacent to the forward end thereof, said lamp adapted to be electrically connected to said dry cell or cells contained within the body; and
a generally parabolic or cone shaped reflector fixedly mounted to the cylindrical lens and located within the cylindrical lens, the reflector having an opening in the centre thereof shaped to receive at least part of the lamp therethrough, the reflector and tubular lens being slideable in an axial direction between an extended position in which the reflector is spaced away from the lamp and light emitting from the lamp in use shines through the tubular lens, and a retracted position in which the lamp extends at least part way through
the opening in the reflector, and light emitting from the lamp in use is reflected in a forward direction by the reflector;
the rearward end of the cylindrical translucent lens being of lesser diameter than the forward end thereof.
Preferably the tubular lens is translucent for substantially its entire length.
Preferably the internal surfaces of said cylindrical lens and/or external surfaces of said body include detent formations so as to hold, at selected locations, said tubular lens relative to said body.
The lighting device may include a strap having one end pivotally connected to the body and the other end having a quick release or bayonet fitting thereon, the body including a first receiving socket therein adapted to receive said second end therein, and the cylindrical sleeve including a second receiving socket for receiving second end therein, the cylindrical sleeve being locked in position relative to the cylindrical lens when the second end is operatively located in said second socket.
Optionally the reflector is of wider diameter than the diameter of the body.
Optionally the back surface of the parabolic reflector can be silvered or moulded in a polymeric or plastic material which is white in colour or otherwise coloured silver or white, to aid in the dispersion of light outwardly through the cylindrical lens when the reflector is in the extended position. It is also possible for the rear surface of the lens to be formed into a shape that further aids the direction of light out through the cylindrical lens when the reflector is in the extended position.
These and further features of the invention are made apparent from the description of an embodiment thereof given below by way of example. In the description reference is made to the accompanying drawings but the specific features shown in the drawings should not be construed as limiting on the invention. In addition, should there be any doubt in the interpretation of this specification, the term xe2x80x9ccomprisedxe2x80x9d or xe2x80x9ccomprisingxe2x80x9d where used in the specification should be interpreted to be an inclusive term rather than an exclusive term.
Throughout the specification the word xe2x80x9ctranslucentxe2x80x9d is used as a description of a character of a material and includes transparent or clear characteristics, and any characteristic which permits the passage or conduction of light therethrough whether or not diffusion occurs.
Where the term xe2x80x9cgenerally cylindricalxe2x80x9d is used in the specification it is not intended to mean that the entire article to which the term is applied must be cylindrical in form. The lens 204, for example, should be interpreted as falling within the scope of the term.